The present invention relates to a data processing device for use in a scintillation camera apparatus.
When a scintillation camera is used to acquire medical diagnostic data (hereinafter referred to simply as data) relating to a living subject under examination, a so-called persistent data acquisition procedure is executed in advance, for placing the subject in the optimum position for acquiring diagnostic data. The data acquired for this purpose is stored sequentially in an acquisition memory and is then displayed on a display device (monitor) as a distribution image of RI (radioisotopes) within the body of the subject. The data stored in the acquisition memory includes information about detected positions and frequencies of events of gamma rays irradiated from RI within the subject's body.
The quantity (the count number) of such data acquired and stored in the acquisition memory increases with time, so that while the density of the RI distribution image on the monitor is low at the early stages of the persistent data acquisition procedure, it is much greater at the later stages thereof. Due to this variation in image density, an image showing crealy the RI distribution cannot easily be obtained. In order to attain a clear image, it is necessary to make frequent manual adjustments using the density level controller of the display device.